1. Field of the Invention
The present invention relates to an image processing apparatus and an image processing method for carrying out an edge enhancement process.
2. Description of the Related Art
Edge enhancement processes in which high-frequency components of images are amplified and image sharpness is enhanced have been carried out for some time in conventional art. In some instances, however, the edge enhancement process entails addition of a wide shoot around edges, so that the periphery of the edge is imparted with a wide white or black fringe. To deal with this problem, some techniques (for instance, Japanese Patent Application Publication Nos. H2-222267 and H4-284069) avoid addition of a wide shoot around edges by multiplying an edge enhancement signal (second-order differentiation signal) by a corrected signal, to correct thereby the edge enhancement signal to a signal that is effective only around a narrow area around the edge.
In the above-described technique, however, the effective range of the edge enhancement signal (region of the image that is affected by the edge enhancement signal) is decided independently of the shape of the edge rise and fall. Accordingly, there are instances where a wide fringe is added around edges in cases of sluggish (gradual) edge rise and fall.